Expertise Via Experience

From emissions to moisture to presses, Pellet Mill Magazine discusses problem-solving, technology and innovation with polished product and service providers.
By Anna Simet | September 27, 2019

Process Prowess
Nestec Inc. President Jim Nester and others at the company have been involved in the wood industry since the early 1990s. Prior to founding Nestec in 1999, the team was involved in pilot testing on wood dryers to determine emissions profiles and how installed equipment was affected, experience that would prove highly valuable when the U.S. wood pellet industry became active. “From that work, we developed a very good understanding of the importance of upstream particulate control ahead of the RTOs (regenerative thermal oxidizers), especially on wood dryers,” Nester says. “Rotary-type dryers are also used in the pellet industry. Understanding the data and how oxidizers are affected allowed for us to quickly modify and properly size and design the equip­ment to effectively handle all emission sources at the pellet mills, including dryer emissions using a WESP (wet electrostatic precipitator), as well as the type of ceramic heat recovery media and velocities through it. Then, we were able to share with potential customers the expected maintenance related to the WESP and the RTO.”

Another component to that previous experience was use of catalysts in regenerative oxidizers. Nestec was involved in one of the first major emissions projects in the U.S. pellet industry, at Waycross-based Georgia Biomass, according to Nester. “We installed two large regenerative catalytic units on the pellet coolers and hammer mills,” he says. “This equipment has been installed since 2013 with the same initial bed of catalysts, so they’ve saved significantly related to operating costs when compared to a traditional RTO. We also de­veloped a unique process ducting de­sign to minimize particulate drop-out and reduce fire risk, including installation of fire detection and suppression systems in the ductwork. All the controls that relate to monitoring and reacting to those systems are something with which we have a lot of experience.”

In the midst of increased scrutiny by NGOs, regulators and the public, some plants are finding themselves in the unforeseen position of being unable to meet their state permit emission levels, and are having to backtrack—that’s where Nestec’s experience comes into play. “We have a very good handle on this and how to help them quickly get back into compliance,” Nester says.

And in the case of those currently being built, getting Nestec involved early on can prevent future problems. “If we’re involved when the permits are being put together, we can provide good data, process flow drawings of similar equipment—we give that full-service engineering support throughout the project.”

On recent innovations, Nester says Nestec has a patent-pending electric actuator design for the main poppet valve system, and most recently successfully designed their standard valve system to replace rotary valve systems that are failing as a result of particulate buildup. “We’re hearing from plants shutting down or tripping out on alarms because of the rotary valves sticking an excessive amount of times a year after they’ve been in for two or three years, getting gummed up with particulate,” he says. “We have a solution to fix,  upgrade and eliminate these nuisance shut downs.”

Diverse Problem-Solving
In the emissions abatement industry for nearly 30 years, Keith Lambert cofounded Oxidizers Inc. in 2013, a company providing service and preventative maintenance, repair and rebuild of thermal oxidizers—and that’s any oxidizer, emphasizes Lambert. “We aren’t OEM-specific—we work on everything, in industries with diverse process streams, so we are familiar with what solutions work best,” he says. “Our diverse portfolio of clients are largely ones who keep experiencing the same problems and keep getting the same answers, so we come in as a third party and figure out exactly what’s going on, and provide solutions to resolve their problems. We offer free online inspections, which is invaluable to begin the diagnosis process.”

As regulations continue to tighten, Oxidizers’ bread and butter is specialized solutions for each customer’s unique process challenge. “In this space, there are issues ranging from chemical and alkali attack, to particulate—a big problem—and of course, general wear and tear,” Lambert says. “Though some OEMs sell specialized systems in particular industry sectors, oftentimes, they sell prepackaged systems regardless of the industry, and that can be problematic. There’s no one-size-fits-all solution to solve every process problem, as it will be different from one customer to another. Facilities have to look at their particular process, and from that vantage point, work in concert with a service provider to determine the best solution, taking into consideration equipment design, feedstock and production rates. In the end, it’s imperative that the backend abatement doesn’t become an anchor to the frontend production. For OEMs, this presents a challenge, making sure that you’re actually designing for the process, rather than your stock design.

Oxidizers has stepped into the arena of system design and supply, a new addition to its offerings. “We built our company in such a way where we flipped the typical model, sales followed by service, to starting on the service side rebuilding a range of systems, and then backed into the OEM side. Having this knowledge set is imperative to the proper design of systems.”

Getting involved in a project early on allows us to determine the need for proper upstream technology if required, Keith points out. “Understanding the physical and chemical parameters associated with the process you have—what type of particulate, alkali attack, silicas, everything plays a role in what hits the RTO and determines the life, or limited life, of the RTO, which should last 25 to 30 years.”

So often, Lambert adds, customers feel isolated and alone, getting the same answers for repeat failures. “I’ve sat in meetings with customers who look like they are in despair. They are in a situation where their abatement equipment is sucking the life out of them and they don’t know what to do. Our goal at Oxidizers is to break through the monotony and frustration that comes from encountering the same issue time and time again, by diagnosing and coming up with customized solutions to help our customers move forward, and experience longevity with their RTOs.”

Managing Moisture  
In 2003, John Fordham and two fellow engineers got together to start MoistTech in Sarasota, Florida, where they decided to take near-infrared (NIR) technology to the next level. “Recognizing such products already exist, our goal was to create not just another NIR moisture gauge, but to analyze the deficiencies of existing gauges and incorporate customer feedback and new technology available together with our extensive knowledge into a superior sensor design,” says MoistTech President Adrian Fordham.

Today, MoistTech manufactures noncontact online sensors able to perform hundreds of measurements per second for thousands of applications. “Most other methods are in contact with the product, which causes the sensors to wear out,” Fordham explains.  “Each sensor is customized to the application.”
When it comes to the wood industry, manufacturing wood pellets requires the refining, drying and blending of wood waste prior to entering the pellet press. For a consistent and on-spec product, feedstock quality, moisture content and consistency matters. “By integrating MoistTech’s IR3000 into the process, users can monitor 100 percent of their product quality, instantly and consistently,” Fordham explains, which often results in significant energy savings in cases that overdrying has been an issue.

Most chip purchasers weigh wet chips but pay chip suppliers based on dry chips delivered, Fordham continues, and to calculate the bone-dry tonnage delivered, a representative chip moisture content is applied to the wet weight of chips delivered to the mill. “MoistTech sensors can be installed at just about every location of incoming material feed—it’s not limited to truck dumpers, stackers and reclaimers,”  he says. “Incoming wood from yard storage can vary largely based on the supplier, weather and season to name a few, so installing the IR3000 above the conveyed material, plant controls can monitor this moisture content instantly and accurately.”

Measuring and controlling moisture can also reduce higher transportation costs due to shipping excess water, and can prevent products from freezing during shipping and transportation. “Testing moisture content throughout the process also provides manufacturers cost savings in energy and fuel costs, as well as having less product waste,” Fordham says. “With continuous NIR online moisture testing, manufacturers can monitor moisture levels to precisely control their dryers to optimize the production process with minimum energy requirements. Reduce downtime, start-up time and waste and energy costs by monitoring the moisture levels at every stage of the process.”

Unlike other instrumentation of this type, some of the unique features of the IR3000—also ideal for installations on chain and screw conveyors—include that it can monitor product even with small gaps in product flow, and is unaffected by ambient light without impacting the accuracy. Fordham adds, “Anywhere that moisture plays a vital role, our sensors can be used.”

Pellet Mill Master   
For the better part of a decade, LM Machinery and Equipment LLC has been serving North American pellet mills—to date, nearly two dozen in the U.S. alone. The company serves as the exclusive North American distributor of La Meccanica s.r.l. di Reffo’s industrial machinery and equipment, a company founded in 1961 in Cittadella, Italy. The family-owned company is dedicated to producing technologically advanced, robust equipment of the highest standards, explains LM Machinery and Equipment President Wladimiro Labeikovsky, providing pellets mills for wood, plastic, animal feed, fertilizer and biomass processing.

But LM’s presence in the wood pellet industry extends beyond its role as an equipment distributor, with a service center in Jacksonville, Florida, that provides on-call service and repair—including refurbishment of dies with state-of-the-art CNC (computer numerical control) machines—not only to its own pellet mills, but also every other major brand of pellet mill, as well as dies, rollers and spare parts. “In addition, along with La Meccanica’s team, we provide hammer mills, pellet coolers, screens—entire pellet product plant proposals from design, engineering or re-engineering, and construction,” Labeikovsky says.

On what LM commonly sees as problematic in the pellet plant operations, Wladimiro says it’s the effects of using low-quality fiber. “The quality of fiber has a big impact on the lifespan of consumable parts like dies and roller shells,” he says. “They may not have any other options, but poor-quality fuel is a big reason for early failure, and some people complain about the equipment, not realizing that it’s the fiber they’re using. The fiber quality affects ash content, and ashes are very abrasive.” 

The company prides itself on customer training, equipping them with the capabilities to properly, efficiently and safely operate equipment. This strategy includes assistance in testing and start-up of equipment, as well as additional periodical refresher courses on-site or in LM’s service center. “We will drop in every so often to see how equipment is performing and being operated,” he says. 

Wladimiro stands by LM Machinery’s commitment to serve customers in a reliable, timely manner and get them what they need as soon as possible, always putting their interests first. “One thing I will tell our customers in the wood pellet industry is that we’re in it for the long haul—we’re here to stay.”